Looking for (Decent) Budget Mic for a DSLR

Hey guys! I'm just stating out with DSLR filmmaking, and I learned very quickly to hate the onboard mic. LOLSo I'm look for a decent mic that I can use attached to my Canon t3i, or use separate and match up in post. My budget is almost non-existent, and I would like to keep it sub $100. My bigest concern really is decent sound quality for the price. Thanks!

I've heard pretty good sound from the Rhode mic (but I don't actually own one).I have an Azden SMX-10 that I got for $60. Its semi-directional, attempting to be a shotgun mic but its really just hyper-cardioid. It works OK and under the right conditions, the sound is quite nice. Plus it is stereo so depending on where you place it you can get some nice separation. But unless you have Magic Lanter on your T3i to manually adjust the levels or record separately on something that you can monitor, the sound is going to be bad.I don't know if that helps or not. I hope it does